Towing mechanism



Dec. 2, 1930. GREEN I 1,783,189

TOWING MECHANISM Filed Aug" 19. 1927 2 Sheets-Sheet l q In men.

EarlEGreem,

Dec. 2, 1930. E. F. GREEN TOWING MECHANISM Filed Aug. 19, 1927 2 Sheets-Sheet 2 Patented Dec. 2, 1930 UNITED. STATES EARL F. GREEN, OEYORK, PENNSYLVANIA TOWING MECHANISM Application filed August 19, 1927. Serial No. 214,085.

of a simple and eflicient device that can readily be applied to a towed vehicle and can be used with a standard service repair truck or other towing vehicle. 7

Further objects of the present invention are the provision of an improved towing hitch and the simplification and improvement generally of certain of the elements tending to improve the combination as a whole.

In usual repair work the disabled vehicle is often at a distance from the repair shop and must be towed in to the garage. Practically all service trucks are equipped at their rear ends with hoists or cranes and the mechanism of the present invention will ordinarily be used in connection with such apparatus.

In the drawings Figure 1 shows aperspective of the device when used without a towing pole.

Figure 2 shows the device including a towin pole.

iigure 3 is a top plan view of the clamp. Figure 3 is a side elevation of the clamp.

Figure 4 is a central vertical section thru the attaching member.

Figure 5 is a vertical section thru the pipe connecting means. In Figure 1 the hoist or crane is shown. in part including the uprights 10, main shaft 11 and superstructure 12, the specific form of the hoisting mechanism however, forming no part of the. present invention. The rods 15 and 16 are each preferably telescopic including a large or outer pipe 1'2: nearer the hoist and pivotally secured to it preferably by means of the-right angular hook 18 which may be slipped into any suitable sized opening and is practically self-locking. The inner sectionof the rod 15 which is preferably a tube, is fixedly. secured to the clamp 20 as by the bolt 21 but the inner section of the rod 16 is pivoted to the clamp as for example,

by the bolt 22, theclamp allowing a considerable angle of movement so that the device.

may be used with the 'two pivotinghooks 18 at varying distances apart and also permitting the rods to be telescoped completely or carried to their extreme length.

The clamp 20 consists of two members, an upper member 23 and a lower member 24, the former having a central lug perforated as at 25 to' receive the angular hook 18 on the brace rod 27 and the latter'including two downwardly extending projections 28 and 29, one of'which carries a latch 30 pivoted as at 31 so as to leave a finger piece 32 convenient of access to lift the latch from engagement with its locking seat 33 on the extension 29. The sections 23 and 24 each contain a spherical seat, the two seats forming together a socket for aball" 35 having an integral perforated ear 37 which may receive a chain to secure the axle or other portion of the disabled Vehicle but which preferably carries the hitch shown.

The towin hitch comprises an attaching member 38 having spaced'and perforated ears 39 on the forward end to receive a bolt or pin 40 for attachment to the towing pole. Two fixed jaws 44 rise vertically from the body of the member 38 and are reinforced by triangular stiffening ribs 45. In line with the jaws and the same distance apart is a pair of extensions 47 perforated at their ends toreceive the pivoting bolt 48 of the hook member 49, the curved hook 50 of which forms a movable jaw to clamp a vehieleaxle for example to the fixed jaws 44. The member 49 extends forwardly in the slot-between the extensions 47' and jaws 44 and has at its rear arcuate end a segmental worm gear 52 by which the bill or hook is turned toward or from the aws 44;

The under side of the attaching member of the hitch has a downwardly and forwardly inclined face 51a and is formed with a cylindrical socket to receive a worm 55 on a shaft 57, which worm engages the gear 52 on the hook member 49. Shaft 57 has a reduced endcircular in cross-section that engages in a. circular recess 58 in the inner wall of the socket, and the shaft and worm are held in place by means of. a cover'plate 60 having ears 61 that seat on ears 62 provided with alined openings through which bolts or rivets are passed to hold the cover plate 60 in position.

Cover plate 60 is provided with an opening to receive the shaft 57 and with a notch 65 to receive the geared sector 52 of the hook member 49. The outer extremity of the shaft 57 may be polygonal in cross section as shown at 66, and 68 is an operating handle for the shaft having spaced ears 69 to receive the polygonal end and being pivotally secured thereto by means of a pin or bolt 70 extending thru the ears and an opening in the end of the shaft.

A convenient method of securing together the two pipes or tubes of each rod is shown in Figure 5. A plug 72, cylindrical if the rod is a tube or to fit the cross section if the member 16 is a pipe, is sweated or brazed into the inner member such as 16 and preferably at the end in such manner that its transverse bore 74 shall aline with the transverse hole 73 in the inner tube and with any one of the holes 75 in the outer sleeve or tube 17. The

plug 72 has a central cylindrical bore 77 which is internally threaded at its outer end 78 and communicates with a smaller bore 7 9 communicating with the transverse bore 74. A detent 80 is pressed by a spring 81 against the shoulder 82 between the two bores and a plug 83 closes the longitudinal bore and confines the spring. A pin 85 provided with a central annular groove 86 and ahead 87 passes thru the alined transverse openings in the tubes and the plug and is resiliently held in place by the detent 80. In the making of this connection I find it convenient to secure the plug 72 to the inner tube before drilling the transverse bore thru the tube and plug as a rather nice degree of fit is required.

In Figure 2 the device is shown including a towing pole 90 which forms no'part of the invention per se but which carries a ball receiving socket 91 at one end and at its other end means for securing it to the integral arm 37 of the ball 35 or the pole itself may have a ball at this end of such size as to be received in the socket of the clamp. By this construction a universal joint is provided between the pole and the clamp and between the pole and the hitch. When the towing pole is used the brace rod 27 which is pivoted by a loose clamp to the main shaft 11 of the hoist crane, is secured by means of its hook 18 thru the opening 25 in the clamp and forms a rigid brace for holding the clamp at a definite spaced relation to the service truck. By insuring that the clamp is no higher than the pivots between the rod-s 15 and 16 and the clamp, the chain of the hoist may be secured to the upstanding web 23 of the clamp but I much prefer the rigid construction illustrated. If the disabled vehicle is carried by an ambulance or two-wheeled truck the ring usually carried at the end of the tongue of the ambulance is slipped into the opening between the downwardly extending members 28 and 29 of the clamp and is held in position by the latch 30 acting quite similarly to the safety catch of jewelry save that the latch 30 is operated by gravity rather than by pull.

When the hitch is used either with or without the towing pole, the jaws 44 are brought into engagement with the axle or other portion of the vehicle to be toward and the hitch lifted until the top faces of the extensions 47 engage this axle or other part. The worm is now turned b means of its handle until the hook or mova le jaw grips the axle firmly. The handle is now dropped and it will swing to vertical position securely locking the jaws in their clamping position due to the angularity. of the worm shaft, thus permitting a rather steeper worm than safe with a vertical worm shaft.

What I claim is 1. In a towing mechanism for a service truck, a clamp, a rod fixedly secured to said clamp and adapted to be pivoted to said truck, a rod pivotally secured to said clamp and to said truck, means for securing a disabled vehicle to said clamp, and means connecting said clamp and truck to hold said clamp at a chosen elevation.

2. In combination, a clamp having a spherical socket therein, a telescopic rod fixedly secured to said clamp and having pivoting means at its free end, a second telescopic rod pivoted to the clamp and having pivoting means at its free end, and hitch means including a ball in said socket for securing a vehicle to be towed to said clamp.

3. In a towing mechanism for a service truck, a clamp, a rod fixedly secured to said clamp and adapted to be pivoted to said truck, a rod pivotally secured to said clamp and to said truck, means for securing a disabled vehicle to said clamp, and means rigidly and adjustably connecting said clamp and truclqto hold said clamp at a chosen elevation.

4. In a pin connection for towing mechanlsm, a pair of telescoping pipes each having transverse bores therein, a plug secured in the inner pipe and having two communicating central longitudinal bores and a transverse bore adapted to aline with a bore of each pipe, a spring pressed detent urged against the shoulder between the longitudinal bores of the plug so as to project slightly into the transverse bore of the plug, and a pin having an annular groove adapted to be engaged by the end of the detent when the pin is passed thru alined bores of the outer pipe, inner pipe, and plug.

5. In combination, a service truck, a clamp fixedly secured in spaced relation thereto by three diverging arms at least two of which are pivoted to the truck, a'hitch, and a towing pole having universal connections with both the clamp and hitch.

6. In combination, a service truck, a clamp fixedly secured in spaced relation thereto by three diverging telescopic arms at least two of which are pivoted to the truck and at least one of which is pivoted to the clamp, a hitch, and a towing pole having universal connections with both the clamp and hitch.

7. In combination, a service truck, a clamp fixedly secured in spaced relation thereto by three diverging arms each pivotally secured to the truck on a horizontal axis, a hitch, and a towing pole having universal connections with both the clamp and hitch.

In testimony whereof I affix my signature.

EARL F. GREEN 

